Ordinance No. 859

Accessory Dwelling Unit (ADU) Standards

Board of Commissioners Work Session

Sept. 10, 2019

Ordinance summary

Proposes amending ADU development standards to:• Implement state

requirements• Reduce barriers to

ADU development

2

What is an ADU?

3

“An interior, attached or detached residential structure that is used in connection with, or that is accessory to, a single-family dwelling”

-DLCD Guidance on Implementing the ADU Requirement under SB 1051

Community benefits of ADUs

ADUs can:• Reduce housing costs for renters and owners• Increase housing variety in neighborhoods• Enable seniors and adult children to live

independently near family members• Optimize use of existing land and infrastructure

4

2017 state requirements• Senate Bill (SB) 1051 in 2017 required:

– Clear and objective standards for housing and clarified that any siting and design regulations must be reasonable

– At least one ADU to be allowed wherever detached single-family dwellings are allowed

• Board addressed these requirements in 2018

5

2018 DLCD recommendations

• Allow two ADUs - one internal and one detached

• Allow internal ADUs to occupy an entire floor

• Remove off-street parking requirements

6

Internal Basement ADU (Photo: Motionspace Architecture, Seattle, WA)

2019 state requirements

House Bill (HB) 2001 in 2019:• Further defined what constitutes a “reasonable

local regulation relating to siting and design”• Determined owner-occupancy and off-street

parking requirements are NOT reasonable regulations for ADUs

7

Proposed amendments

• Update references, clarify content, minor reorganization

• As required by State:– Allow ADUs in remainder of districts where

detached single-family dwellings are allowed– Remove parking and owner-occupancy

requirements for ADUs

8

Proposed amendments

• Allow two ADUs - one attached/internal and one detached

• Allow attached/internal ADUs to occupy 800 square feet or an entire floor

• Allow occupancy of an ADU before occupancy of the primary dwelling

• Allow home occupations as allowed by the underlying district

9

Proposed amendments

• Modify design standards for increased flexibility– Maximum height– Entrance location– Rear/side yard

requirements– Setbacks on corner lots

10

Planning Commission

• Discussed: – Applicability of System Development Charges

(SDCs) for ADUs– Adequacy of urban services for increased ADU

construction• Voted 6-0 to recommend approval of

Ordinance No. 859 to the Board

11

Staff recommendation

• Conduct the public hearing on Sept. 17 • At the conclusion of public testimony,

adopt Ordinance No. 859 and associated findings

12

Questions or comments?

For more information, please contact:

Bryan Robb, Associate Plannerbryan_robb@co.washington.or.us

503-846-3717

13